Error when file is not found

[bkamins]

The message in

CSV.jl/src/context.jl

Line 179 in 0eaacb4

throw(ArgumentError("\"$source\" is not a valid file"))

is reported to be misleading by the users.

Maybe we could split the isfile condition to a separate test and if file is not found report that it was not found? (users think that "valid file" means that file exists but did not pass validation)

[nickrobinson251]

Do we need to split out the isfile condition or just change the wording in this one check (e.g. to "No such file \"$source\"")?

i.e. does this error ever get triggered except for non-existent filepaths? I tried to trigger it by passing in various silly arguments to CSV.File (e.g. md files, xml files, Vector{UInt16}) and couldn't trigger it -- either i hit a different error (usually isfile throwing an error) or reading succeeded (turn's out CSV.jl will read markdown somewhat successfully!)

[bkamins]

Indeed isfile will throw an error if something that is not a file is passed to it. However, I think we could consider adding a restriction that we accept AbstractString here (and then throw "file not found") or on any other type throw an error?

The issue is that isfile calls stat which has the following methods:

julia> methods(stat)
# 7 methods for generic function "stat":
[1] stat(s::IOStream) in Base at iostream.jl:57
[2] stat(fd::Base.Libc.WindowsRawSocket) in Base.Filesystem at stat.jl:79
[3] stat(path::AbstractString) in Base.Filesystem at stat.jl:80
[4] stat(fd::RawFD) in Base.Filesystem at stat.jl:83
[5] stat(fd::Integer) in Base.Filesystem at stat.jl:85
[6] stat(f::Base.Filesystem.File) in Base.Filesystem at filesystem.jl:246
[7] stat(path...) in Base.Filesystem at stat.jl:109

And I am not sure all of them are properly handled later by CSV.File, e.g. is this expected:

julia> CSV.File(1)
0-element CSV.File{false}

?

[nickrobinson251]

we could consider adding a restriction that we accept AbstractString here

I think this would break FilePathsBase.AbstractPath, which are currently supported due to the lack of type constraints (or require us adding a FilePathsBase dependency)

[bkamins]

I am flexible here - maybe even CSV.File supports all that stat supports - @quinnj will know hopefully.

[quinnj]

How about #863?